Pneumatic rapier for inserting weft thread into warp sheds

ABSTRACT

A rapier for inserting a weft thread into a warp shed, in which a tube is located in a casing, with one end of the tube being connected to an attachment for generating therein a pressure flow, and the other end projecting from the casing, with its butt being sheared at an acute angle so that the far end of the shear is the closest to the reed, and the near end the closest to the fabric fell.

United States Patent Makachev et al. July 18, 1972 PNEUMATIC RAPIER FORINSERTING R f rences Cited WEFT THREAD INTO WARP SHEDS UNITED STATESPATENTS 2] Inventors: Nikolai Ivmvkh Mnlmlnv, ulitsa j 3,367,371 2/1968Mullekom ..1a9/127 py, 12, korpus 1, kv. 27; Alexei 1,721,940 7/1929Ballou ..l78/18 Nlkolaevich Parshln, Nagomaya ulitsa, 34, korpus 43, kv.53, both of Moscow, FOREIGN PATENTS OR APPLICATIONS 1,261,463 4/1961France....; ..139/127 P [22] m June 10, 1970 161,669 5/1963 U.S.S.R...l39/ 127 P PP 45,003 Primary Examiner-Henry S..1audon Attorney-Holman& Stern I [30] Foreign Application Priority Data ABSTRACT I 23 i Arapier for inserting a wefl thread into a warp shed, in which y a tubeis located in a casing, with one end of the tube being connected to anattachment for generating therein a pressure flow, and the other endprojecting from the casing, with its 58 Field s h 1 39/122427 butt beingsheared at an acute angle so that the far end of the l 1 shear is theclosest to the reed, and the near end the closest to the fabric fell.

2 China, 4 Drawing Figures PATENTED JUL 1 8 I972 IIIIII'IIIIIIII'IIIII,Zwhm

PNEUMATIC RAPIER FOR INSERTING WEFI THREAD INTO WARP SHEDS BACKGROUND OFTHE INVENTION- The present invention relates to devices for inserting athread into the warp shed, and more specifically to rapiers for use inair jet looms.

Widely known in the art are rapiers for weft thread insertion,comprising a tube located in a casing, with one end of the tube beingconnected to an attachment for generating therein a pressure flow todeliver the end of the weft thread into the warp shed, while the otherend of the tube terminates inside the casing in the form of a cap, or apipe. The cap or pipe is sheared at its end, thus being sharpened for amore accurate separation of the warp threads forming the shed, andprojects beyond the end of the inner tube. The attachment generating thepressure flow is connected to the tube through a chamber and a socket,and the weft thread is introduced into this tube through a sleevelocated some distance from the tube end.

In these rapiers, the sharp shear distorts the air flow emerging fromthe tube, which involves an inaccurate transfer of the end of the weftthread to the receiving (suction) rapier, and correspondingly leads todefects the fabric, i.e., short flights of the weft thread.

In addition, location of the sleeve some distance from the tube endcauses air eddying inside the chamber, with part of the air being thrownout into the atmosphere through the sleeve hole, thereby leading to awaste of compressed air, and to a reduced tension of the weft thread.This affects the quality of the weft thread insertion into the shedformed by the warp threads.

SUMMARY OF THE INVENTION The basic object of the invention is to providea rapier for weft thread insertion into the warp shed, with such adesign of the tube, that the compressed air flow in the rapier is, atboth the tube inlet and outlet, more organized, not distorted and noteddying, and at the same time ensuring a quality insertion of the weftthread into the warp shed.

With this object in view, the rapier for weft thread insertion into thewarp shed, includes a tube in a casing, one end of the.

tube being connected to an attachment generating therein a pressure flowto deliver the end of a weft thread into the warp shed, the free end ofthe tube, according to the invention, projecting from the casing in thedirection of the weft thread movement, and being sheared at an angle sothat the far end of the shear is the closest to the reed, while the nearend is the closest to the fabric fell.

Such a design completely prevents the distortion and eddying of the airflow at the outlet from the tube, and respectively provides for a moreaccurate transfer of the weft thread end into the receiving rapier.

The projecting end of the tube is preferably narrowed whereby the airflow is still more concentrated.

In the present rapier the tube end connected to the air pressurizingattachment may be shaped as a restriction, adjoining which restrictionare a threaded sleeve provided with a hole for passing the weft thread,and a socket leading from a compressed air source. This arrangementprevents the detrimental effect of air eddying inside the chamber andthe sleeve hole on the weft thread, and also eliminates air wastage intothe atmosphere, thus improving the weft thread insertion into the warpshed, reducing air consumption, and improving the threading of the weftthread into the threaded sleeve.

To obtain a clearer idea of the invention, the following is adescription of a particular exemplary embodiment thereof with referenceto the appended drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general front view of therapier according to the invention;

FIG. 2 is a fragmentary top view, partly in elevation and partly insection of the tube end projecting from the casing;

FIG. 3 is a fragmentary view in section of another embodiment of theprojecting tube end; and

FIG. 4 is a fragmentary sectional view showing the tube end connected tothe air pressurizing attachment.

DETAILED DESCRIPTION OF THE INVENTION The rapier comprises a casing 1(FIG. 1) in which a tube 2 is located and a reciprocatory movement isimparted to the rapier (the rapier movement is conventionally shown byarrow A) through a system of hollow levers 3 and 4, with the lever 3being connected by socket 5 to one end of the tube 2. The lever 4 ismounted on a hollow rotating shaft 6 to which is secured a nipple 7, andconnected to the nipple is piping 8 communicating with a source ofcompressed air (not shown). The movement of the compressed air isconventionally shown by arrow B. A free end 9 (FIG. 2) of the tube 2projects from the casing l and extends into the shed formed by warpthreads 10. A butt ll of the end 9 sheared at an angle, thus beingsharpened so that the far end of the shear is the closest to a reed 12,while the near end' thereof is the closest to fell 13 of a fabric 14.

Such a design of the tube precludes the air flow eddying at the outlettherefrom, and respectively provides for a more accurate transfer of theend of a weft thread 15 into the receiving rapier (not shown).

To obtain a more concentrated air flow, the free end 9 of tube 2 narrowsas shown in FIG. 3.

Adjoining opposite end 16 (FIG. 4) of the tube 2 are a threaded sleeve17 with an opening 18 for the weft thread 15, and the socket 5, whichembraces the sleeve 17, thus forming a chamber 19. The walls of the end16 of the tube 2 in the place, where the tube adjoins the sleeve, areconstricted. Such a design secures an efi'ect of ejection for a reliableaspiration of the weft thread into the sleeve 17. However, the end 16 ofthe tube 2 can be straight and in this case, there is also created anejection effect, but such effect is a weaker one.

To lay the weft thread 15 into the warp shed, the casing l (i.e. therapier) has reciprocatory movement impartedthereto from the rotatingshaft 6 through the hollow levers 3 and 4. At thesame time, cleancompressed air is fed through piping, nippie 7, hollow shaft 6, andhollow levers 3 and 4 into the socket 5. The compressed air enters thechamber 19, and then through the end 16 of the tube 2, with an ejectioneffect being created at such location thereby ensuring air aspirationfrom the atmosphere into the opening 18 of the sleeve 17. To threadtheweft thread 15, such thread is positioned near the opening 18, and isdrawn into the opening of the sleeve 17. By meeting no detrimental aireddies in its path in the chamber 19, the thread 15 passes into the tube2, in which it is main tained in tension by the air flow, and then,together with the rapier, is forwarded into the warp shed to betransferred into the receiving rapier. The air flow entrains the thread15, and emerges from the end 9 of the tube 2 in a concentrated form,without eddies or distortions, and as it meets the receiving rapier, ittransfers the thread into the suction flow of the receiving rapier; Theair flow emerging from the narrowed end 9 of rapier 2 (another version)is still more concentrated. Passing through the rapier, the thread 15 islaid down in the warp :shed, and is then beaten by the reed 12.

What we claim is:

1. A rapier for inserting a weft thread into a warp shed of a loomhaving a reed, including a casing, a tube located in an extendingaxially of the casing, said tube having opposite ends, a socket attachedto the casing and extending laterally therefrom adjacent one end of thetube, a sleeve embraced by the socket and having a bore for a weftthread, the bore communicating with the interior of the tube at said oneend thereof, the other end of the tube projecting from the end of thecasing in the direction of wefi thread movement, the butt of said otherend of the tube being sheared at an angle and thereby sharpened, withthe far end of the shear being closest to the reed and the near endbeing closest to the fell of the fabric, the tube adjacent said one endthereof having a constriction, and said socket communicating with asource of compressed air for drawing the weft thread into the sleevebore and thence into the tube for movement into the warp shed.

2. The rapier as claimed in claim 1, wherein the other end of the tubenarrows in the direction of the weft thread movement.

1. A rapier for inserting a weft thread into a warp shed of a loomhaving a reed, including a casing, a tube located in an extendingaxially of the casing, said tube having opposite ends, a socket attachedto the casing and extending laterally therefrom adjacent one end of thetube, a sleeve embraced by the socket and having a bore for a weftthread, the bore communicating with the interior of the tube at said oneend thereof, the other end of the tube projecting from the end of thecasing in the direction of weft thread movement, the butt of said otherend of the tube being sheared at an angle and thereby sharpened, withthe far end of the shear being closest to the reed and the near endbeing closest to the fell of the fabric, the tube adjacent said one endthereof having a constriction, and said socket communicating with asource of compressed air for drawing the weft thread into the sleevebore and thence into the tube for movement into the warp shed.
 2. Therapier as claimed in claim 1, wherein the other end of the tube narrowsin the direction of the weft thread movement.